TY - JOUR AU - Mennicken, Max AU - Peter, Sophia Katharina AU - Kaulen, Corinna AU - Simon, Ulrich AU - Karthäuser, Silvia ID - 16960 JF - The Journal of Physical Chemistry C KW - pc2-ressources SN - 1932-7447 TI - Controlling the Electronic Contact at the Terpyridine/Metal Interface ER - TY - JOUR AU - Tönnies, Merle AU - Henneböhl, Dennis ID - 17057 IS - 2 JF - Journal for the Study of British Cultures TI - Negotiating Images of (Un-)Belonging and (Divided) Communities: Ali Smith's Seasonal Quartet as a Counter-Narrative to Brexit VL - 26 ER - TY - JOUR AB - Cyanobacteriochromes are compact and spectrally diverse photoreceptor proteins that are promising candidates for biotechnological applications. Computational studies can contribute to an understanding at a molecular level of their wide spectral tuning and diversity. In this contribution, we benchmark methods to model a 110 nm shift in the UV/Vis absorption spectrum from a red- to a green-absorbing form of the cyanobacteriochrome Slr1393g3. Based on an assessment of semiempirical methods to describe the chromophore geometries of both forms in vacuo, we find that DFTB2+D leads to structures that are the closest to the reference method. The benchmark of the excited state calculations is based on snapshots from quantum mechanics/molecular mechanics molecular dynamics simulations. In our case, the methods RI-ADC(2) and sTD-DFT based on CAM-B3LYP ground state calculations perform the best, whereas no functional can be recommended to simulate the absorption spectra of both forms with time-dependent density functional theory. Furthermore, the difference in absorption for the lowest energy absorption maxima of both forms can already be modelled with optimized structures, but sampling is required to improve the shape of the absorption bands of both forms, in particular for the second band. This benchmark study can guide further computational studies, as it assesses essential components of a protocol to model the spectral tuning of both cyanobacteriochromes and the related phytochromes. AU - Wiebeler, Christian AU - Schapiro, Igor ID - 17077 JF - Molecules KW - pc2-ressources SN - 1420-3049 TI - QM/MM Benchmarking of Cyanobacteriochrome Slr1393g3 Absorption Spectra ER - TY - GEN AU - Oevel, Gudrun AU - Graf-Schlattmann, Marcel AU - Meister, Dorothee M. AU - Wilde, Melanie ID - 17157 TI - Digitaler Wandel als strategischer Transformationsprozess – Zum allgemeinen und hochschulspezifischen Verständnis der Digitalisierung ER - TY - JOUR AU - Oevel, Gudrun AU - Barlösius, Eva ID - 17160 JF - Zeitschrift für Bibliothekswesen und Bibliographie SN - 0044-2380 TI - Quo vadis, Fachinformationsdienste? Ein Überblick über die Ergebnisse der Evaluierung des Förderprogramms »Fachinformationsdienste« für die Wissenschaft ER - TY - CONF AB - State-of-the-art frameworks for generating approximate circuits automatically explore the search space in an iterative process - often greedily. Synthesis and verification processes are invoked in each iteration to evaluate the found solutions and to guide the search algorithm. As a result, a large number of approximate circuits is subjected to analysis - leading to long runtimes - but only a few approximate circuits might form an acceptable solution. In this paper, we present our Jump Search (JS) method which seeks to reduce the runtime of an approximation process by reducing the number of expensive synthesis and verification steps. To reduce the runtime, JS computes impact factors for each approximation candidate in the circuit to create a selection of approximate circuits without invoking synthesis or verification processes. We denote the selection as path from which JS determines the final solution. In our experimental results, JS achieved speed-ups of up to 57x while area savings remain comparable to the reference search method, Simulated Annealing. AU - Witschen, Linus Matthias AU - Ghasemzadeh Mohammadi, Hassan AU - Artmann, Matthias AU - Platzner, Marco ID - 10577 KW - Approximate computing KW - design automation KW - parameter selection KW - circuit synthesis SN - 9781450362528 T2 - Proceedings of the 2019 on Great Lakes Symposium on VLSI - GLSVLSI '19 TI - Jump Search: A Fast Technique for the Synthesis of Approximate Circuits ER - TY - JOUR AU - Tagne, V. K. AU - Fotso, S. AU - Fono, L. A. AU - Hüllermeier, Eyke ID - 10578 IS - 2 JF - New Mathematics and Natural Computation TI - Choice Functions Generated by Mallows and Plackett–Luce Relations VL - 15 ER - TY - CONF AB - We consider the problem of transforming a given graph G_s into a desired graph G_t by applying a minimum number of primitives from a particular set of local graph transformation primitives. These primitives are local in the sense that each node can apply them based on local knowledge and by affecting only its 1-neighborhood. Although the specific set of primitives we consider makes it possible to transform any (weakly) connected graph into any other (weakly) connected graph consisting of the same nodes, they cannot disconnect the graph or introduce new nodes into the graph, making them ideal in the context of supervised overlay network transformations. We prove that computing a minimum sequence of primitive applications (even centralized) for arbitrary G_s and G_t is NP-hard, which we conjecture to hold for any set of local graph transformation primitives satisfying the aforementioned properties. On the other hand, we show that this problem admits a polynomial time algorithm with a constant approximation ratio. AU - Scheideler, Christian AU - Setzer, Alexander ID - 10586 KW - Graphs transformations KW - NP-hardness KW - approximation algorithms T2 - Proceedings of the 46th International Colloquium on Automata, Languages, and Programming TI - On the Complexity of Local Graph Transformations VL - 132 ER - TY - JOUR AB - We present a new framework for optimal and feedback control of PDEs using Koopman operator-based reduced order models (K-ROMs). The Koopman operator is a linear but infinite-dimensional operator which describes the dynamics of observables. A numerical approximation of the Koopman operator therefore yields a linear system for the observation of an autonomous dynamical system. In our approach, by introducing a finite number of constant controls, the dynamic control system is transformed into a set of autonomous systems and the corresponding optimal control problem into a switching time optimization problem. This allows us to replace each of these systems by a K-ROM which can be solved orders of magnitude faster. By this approach, a nonlinear infinite-dimensional control problem is transformed into a low-dimensional linear problem. Using a recent convergence result for the numerical approximation via Extended Dynamic Mode Decomposition (EDMD), we show that the value of the K-ROM based objective function converges in measure to the value of the full objective function. To illustrate the results, we consider the 1D Burgers equation and the 2D Navier–Stokes equations. The numerical experiments show remarkable performance concerning both solution times and accuracy. AU - Peitz, Sebastian AU - Klus, Stefan ID - 10593 JF - Automatica SN - 0005-1098 TI - Koopman operator-based model reduction for switched-system control of PDEs VL - 106 ER - TY - JOUR AB - In this article we show that the boundary of the Pareto critical set of an unconstrained multiobjective optimization problem (MOP) consists of Pareto critical points of subproblems where only a subset of the set of objective functions is taken into account. If the Pareto critical set is completely described by its boundary (e.g., if we have more objective functions than dimensions in decision space), then this can be used to efficiently solve the MOP by solving a number of MOPs with fewer objective functions. If this is not the case, the results can still give insight into the structure of the Pareto critical set. AU - Gebken, Bennet AU - Peitz, Sebastian AU - Dellnitz, Michael ID - 10595 IS - 4 JF - Journal of Global Optimization SN - 0925-5001 TI - On the hierarchical structure of Pareto critical sets VL - 73 ER - TY - CONF AB - In comparison to classical control approaches in the field of electrical drives like the field-oriented control (FOC), model predictive control (MPC) approaches are able to provide a higher control performance. This refers to shorter settling times, lower overshoots, and a better decoupling of control variables in case of multi-variable controls. However, this can only be achieved if the used prediction model covers the actual behavior of the plant sufficiently well. In case of model deviations, the performance utilizing MPC remains below its potential. This results in effects like increased current ripple or steady state setpoint deviations. In order to achieve a high control performance, it is therefore necessary to adapt the model to the real plant behavior. When using an online system identification, a less accurate model is sufficient for commissioning of the drive system. In this paper, the combination of a finite-control-set MPC (FCS-MPC) with a system identification is proposed. The method does not require high-frequency signal injection, but uses the measured values already required for the FCS-MPC. An evaluation of the least squares-based identification on a laboratory test bench showed that the model accuracy and thus the control performance could be improved by an online update of the prediction models. AU - Hanke, Soren AU - Peitz, Sebastian AU - Wallscheid, Oliver AU - Böcker, Joachim AU - Dellnitz, Michael ID - 10597 SN - 9781538694145 T2 - 2019 IEEE International Symposium on Predictive Control of Electrical Drives and Power Electronics (PRECEDE) TI - Finite-Control-Set Model Predictive Control for a Permanent Magnet Synchronous Motor Application with Online Least Squares System Identification ER - TY - JOUR AU - Khan, Gohar Feroz AU - Trier, Matthias ID - 10792 IS - 4 JF - European Journal of Information Systems SN - 0960-085X TI - Assessing the long-term fragmentation of information systems research with a longitudinal multi-network analysis VL - 28 ER - TY - CONF AU - Potthast, Martin AU - Gienapp, Lukas AU - Euchner, Florian AU - Heilenkötter, Nick AU - Weidmann, Nico AU - Wachsmuth, Henning AU - Stein, Benno AU - Hagen, Matthias ID - 11709 T2 - 42nd International ACM Conference on Research and Development in Information Retrieval (SIGIR 2019) TI - Argument Search: Assessing Argument Relevance ER - TY - GEN AU - Wachsmuth, Henning ID - 11713 IS - 3 T2 - Computational Linguistics TI - Book Review: Argumentation Mining VL - 45 ER - TY - CONF AU - Ajjour, Yamen AU - Wachsmuth, Henning AU - Kiesel, Johannes AU - Potthast, Martin AU - Hagen, Matthias AU - Stein, Benno ID - 11714 T2 - Proceedings of the 42nd Edition of the German Conference on Artificial Intelligence TI - Data Acquisition for Argument Search: The args.me Corpus ER - TY - JOUR AB - Advances in electromyographic (EMG) sensor technology and machine learning algorithms have led to an increased research effort into high density EMG-based pattern recognition methods for prosthesis control. With the goal set on an autonomous multi-movement prosthesis capable of performing training and classification of an amputee’s EMG signals, the focus of this paper lies in the acceleration of the embedded signal processing chain. We present two Xilinx Zynq-based architectures for accelerating two inherently different high density EMG-based control algorithms. The first hardware accelerated design achieves speed-ups of up to 4.8 over the software-only solution, allowing for a processing delay lower than the sample period of 1 ms. The second system achieved a speed-up of 5.5 over the software-only version and operates at a still satisfactory low processing delay of up to 15 ms while providing a higher reliability and robustness against electrode shift and noisy channels. AU - Boschmann, Alexander AU - Agne, Andreas AU - Thombansen, Georg AU - Witschen, Linus Matthias AU - Kraus, Florian AU - Platzner, Marco ID - 11950 JF - Journal of Parallel and Distributed Computing KW - High density electromyography KW - FPGA acceleration KW - Medical signal processing KW - Pattern recognition KW - Prosthetics SN - 0743-7315 TI - Zynq-based acceleration of robust high density myoelectric signal processing VL - 123 ER - TY - CHAP AU - Senft, Björn AU - Rittmeier, Florian AU - Fischer, Holger Gerhard AU - Oberthür, Simon ID - 11952 SN - 0302-9743 T2 - Design, User Experience, and Usability. Practice and Case Studies TI - A Value-Centered Approach for Unique and Novel Software Applications ER - TY - JOUR AB - As flexible optical devices that can manipulate the phase and amplitude of light, metasurfaces would clearly benefit from directional optical properties. However, single layer metasurface systems consisting of two-dimensional nanoparticle arrays exhibit only a weak spatial asymmetry perpendicular to the surface and therefore have mostly symmetric transmission features. Here, we present a metasurface design principle for nonreciprocal polarization encryption of holographic images. Our approach is based on a two-layer plasmonic metasurface design that introduces a local asymmetry and generates a bidirectional functionality with full phase and amplitude control of the transmitted light. The encoded hologram is designed to appear in a particular linear cross-polarization channel, while it is disappearing in the reverse propagation direction. Hence, layered metasurface systems can feature asymmetric transmission with full phase and amplitude control and therefore expand the design freedom in nanoscale optical devices toward asymmetric information processing and security features for anticounterfeiting applications. AU - Frese, Daniel AU - Wei, Qunshuo AU - Wang, Yongtian AU - Huang, Lingling AU - Zentgraf, Thomas ID - 11953 IS - 6 JF - Nano Letters SN - 1530-6984 TI - Nonreciprocal Asymmetric Polarization Encryption by Layered Plasmonic Metasurfaces VL - 19 ER - TY - JOUR AU - Li, Tianyou AU - Wei, Qunshuo AU - Reineke, Bernhard AU - Walter, Felicitas AU - Wang, Yongtian AU - Zentgraf, Thomas AU - Huang, Lingling ID - 11955 IS - 15 JF - Optics Express SN - 1094-4087 TI - Reconfigurable metasurface hologram by utilizing addressable dynamic pixels VL - 27 ER - TY - CONF AB - We present an unsupervised training approach for a neural network-based mask estimator in an acoustic beamforming application. The network is trained to maximize a likelihood criterion derived from a spatial mixture model of the observations. It is trained from scratch without requiring any parallel data consisting of degraded input and clean training targets. Thus, training can be carried out on real recordings of noisy speech rather than simulated ones. In contrast to previous work on unsupervised training of neural mask estimators, our approach avoids the need for a possibly pre-trained teacher model entirely. We demonstrate the effectiveness of our approach by speech recognition experiments on two different datasets: one mainly deteriorated by noise (CHiME 4) and one by reverberation (REVERB). The results show that the performance of the proposed system is on par with a supervised system using oracle target masks for training and with a system trained using a model-based teacher. AU - Drude, Lukas AU - Heymann, Jahn AU - Haeb-Umbach, Reinhold ID - 11965 T2 - INTERSPEECH 2019, Graz, Austria TI - Unsupervised training of neural mask-based beamforming ER -